Device for protecting or containing submerged surfaces, more particularly the hulls of vessels

ABSTRACT

A device for the containment, protection and/or treatment of a submerged surface such as a ship hull, includes a flexible and impervious or non-impervious shell, including two portions, an emerged portion ( 1 ) and a submerged portion ( 2 ) having different features.

TECHNICAL FIELD OF THE INVENTION

The invention relates generally to the protection and/or treatment of asubmerged surface such as a ship hull.

More particularly, it relates to a device for the containment,protection and/or treatment of a submerged surface such as a ship hull(other non-limiting examples: surfaces in contact with water: fingerpier, beacon, offshore platform, dock, barge, swimming pool, pond,floating homes) comprising an impervious or semi-impervious flexibleshell made of several portions: a mainly submerged lower portion and amostly emerged upper portion.

TECHNICAL BACKGROUND

All of the surfaces of objects, structures, ships or buildings submergedin water cover with algae or molluscs. To avoid or minimize thisproblem, the most frequently used method is antifouling (most oftenthrough paint biocide). However, firstly, this technique forces to cleanthe hull and repaint it every year, thus drydocking the ship. Secondly,continuing contact between the anfoulings and surrounding water causesmajor direct and indirect pollution in ports and bays.

Many patents were filed relating to the protection of the hull thatoffer an alternative to this technique; a shell is slipped under thehull (FIGS. 1 and 2) to prevent or minimize the growth of theseorganisms. These previous patents have widely described the protectingsystem, with or without pumping residual water between the hull and theshell.

Some literature describes devices in which the residual water betweenthe impervious film and the hull is pumped to allow the hull out of thewater, the efficiency of which depends on the device. Other devices keepthis residual water trapped, preventing the growth of the aforementionedorganisms for lack of movement and light. Other devices add a productdestroying living organisms to the residual water. All these devicesexhibit the same drawback: providing a material the features of whichare suitable for both the emerged and submerged portions and combiningall the desired features essential for sustainability in the conditionsof use is very difficult.

Still, some materials combine most of the desirable features, but at avery high cost and with an excessive specific gravity. For example,Teflon could be used if not for its price; the cost of production wouldnot allow mass marketing, thus remaining mostly a technical solution.

Another issue occurred during previous development attempts. Marineorganisms cling to the outer side of the shell. They grow all the easieras this surface is not coated with antifouling paint biocide. Afterabout ten months, it is therefore covered with a very large amount ofalgae and molluscs. Thus, the surface should be cleaned; this procedureis not always practical. In addition, some films or webs are fragile;marine organisms have a high adhesion capacity, thus getting moredifficult to dislodge over the years (the surface being altered andtherefore facilitating their development and adhesion). Mechanicalbrushing is thus often necessary, leading to a fast degradation of thesurfaces. Stronger webs, on the other hand, should be thickened orstrengthened with a fabric or fiber, deteriorating flexibility andespecially weight features.

Although the cleaning is easier than that of the hull of the ship, whichrequires drydocking and renewal of antifouling, this procedure remainsunpractical. In order to demonstrate the difficulty of reconciling allthe features and although

-   -   the principle of the previously described device has an        undeniable effectiveness,    -   the first patent was filed more than 50 years ago,    -   there have been few development attempts,        it should be noted that no comparable device has been        sustainably marketed.

SUBJECT-MATTER OF THE INVENTION

To overcome the aforementioned drawbacks of the prior art, the presentinvention provides a device hereinafter called “shell” which consists ofat least two discrete portions: an emerged portion (1) and a submergedportion (2), with several variants. This simplifies the manufacture ofthe device by separating the abovementioned issues. The features of eachportion can thus be optimized, allowing for the selection of materialswith distinct properties, adapted to the respective media and desiredcharacteristics.

In brief

For the upper emerged portion 1, the main features are: mechanicalstrength (for example tensile strength above 10N/mm² or 10 MPa) andultraviolet light resistance. The small surface area of this portionwill allow for more expensive materials (specially formulated andoptionally displaying a difference in specific gravity or weight vs. thesubmerged portion).

For the lower submerged portion 2, the main features are: flexibility,low specific gravity (less than 1), ease of cleaning, hydrophobicity,lightness, resistance to materials and substances with which it is incontact (propeller, rudder, antifouling or even detergent). Indeed,despite their dramatic evolution, some antifouling products remainpolluting and aggressive. For special treatment of the hull, it willalso be of interest to use the device as a containment device. Thematerial can thus be chosen depending on the treatments.

Other advantageous and non-limiting features of the device according tothe invention are as follows:

-   -   The upper portion 1 and the lower portion 2 of the shell have at        least a difference chosen between the following differences; the        respective outer sides of the two portions 1 and 2 are made of        different materials, portions 1 and 2 have different        thicknesses.    -   The upper portion 1 and the lower portion 2 are permanently        assembled and affixed to each other.    -   The upper portion 1 and the lower portion 2 are temporarily        assembled.    -   The upper portion 1 and the lower portion 2 of the shell are        made of materials of different densities.    -   The upper portion 1 of the shell is made, at least on its outer        side, of PVC and the lower portion 2 of the shell is mainly made        of a polyolefin.    -   The upper portion 1 of the shell consists of a plurality of        layers of separate materials, complexed or not to each other.    -   The upper portion 1 of the shell comprises at least two layers,        including a substrate and an outer coating film onto the        substrate which has higher UV resistance than the substrate.    -   The upper portion 1 of the shell comprises an inner layer on the        side of the object to protect or included in a hem and is made        of a material of specific gravity lower than 0.9.    -   The lower portion 2 of the shell has a specific gravity of less        than 1.    -   The lower portion 2 of the shell has a weight of less than 0.5        g/m².    -   The lower portion 2 of the shell consists of a plurality of        layers of separate materials, complexed or not to each other.    -   The lower portion 2 of the shell comprises at least one outer        layer that is at least partially separable.    -   The lower portion 2 of the shell is made at least on its outer        side opposite to the object to protect in a treated material        which is formulated to provide anti-adhering properties.    -   The upper portion 1 of the shell is provided with means for        fastening to the object to protect.

DETAILED DESCRIPTION OF AN EMBODIMENT

The following description, with reference to the appended drawings isgiven as a non limiting example and will allow for understanding theinvention and how it can be embodied for a ship.

Appended drawings:

FIGS. 1 and 2 show a view of a containment device, the protective and/ortreatment shell according to the invention, arranged on the mostlysubmerged portion of the hull of a ship.

FIGS. 3, 4, 5, and 6 show diagrams of shells of various forms made oftwo portions, 1 and 2, building up the device, to adapt to differenttypes of ships.

FIGS. 7, 8 and 9 show a type of final assembly of the two portions 1 and2 building up the device;

FIGS. 10, 11, 12, 13 and 14 show temporary types of assemblies, withportions 1 and 2 separable or partly separable.

FIGS. 15, 16, 17, 18, 19, and 20 show various types of films.

FIGS. 21, 22, 23 show the possibility of adding a foamed plastic to theemerged portion 1.

FIGS. 24 to 27 show variants of the closure of the rear portion.

FIGS. 28 to 31 show one possible setting up of the shell.

The entire device consists of

In the main embodiment, the device consists of at least two mainportions 1 and 2 having features (physical or chemical) adapted to theirrespective different media: an emerged portion 1 surrounding the hull ofthe ship at or from the waterline, and secondly, a submerged portion 2of a surface area always greater than the preceding, which includes theentirety of the submerged portion to protect 5 (in this example the hullof the ship), both portions 1 and 2 being assembled permanently, bystitching, gluing or welding fasteners, rivets 3 (FIGS. 7-9).

In this embodiment, the upper emerged portion 1 is made of a flexiblematerial whose two main features are mechanical strength, (for exampletensile strength above 10N/mm² or 10 MPa), tear, lengthening andweathering resistance (particularly UV resistance). Flexibility isrequired as well as water resistance, but these features are lesscritical, the portion being only very partially in contact with water.Non limiting examples of materials: fabrics, films or PVC webs, nylon,polyurethane or polyurethane webbing, specially formulated PE or PP withadditives or anti UV agents, reflective layer, complex combining thementioned materials, . . .

In this embodiment, the constituent material of the outer side of atleast the upper portion is thus selected for imparting to said upperportion a resistance to ultraviolet (UV) radiation that is higher thanfor the lower portion.

Higher resistance to ultraviolet (UV) radiation refers to the fact thatthe material comprising at least the outer portion of the upper portionretains a mechanical strength (tensile, break, shear) that is at least 3times that of the lower portion, when they (emerged upper portion andlower portion) are directly exposed in an identical manner (sameintensity, same duration, same wavelength) equaling a mean exposition insouthern France for three years.

Other method of UV resistance characterization.

After being exposed for 3 years to the above described conditions, thematerial comprising at least the outer surface of the upper portion mustretain at least 70% of its tensile strength, its tear resistance or itsshear strength. Example: this material comprising at least the outersurface of the upper portion and having before exposition a tensilestrength of 10N/mm² (10 MPa) must retain a tensile strength of at least7N/mm² (7 MPa) after 3 years of exposition to the above describedconditions.

On the other hand, after being exposed for 3 years to the same abovedescribed conditions, the material comprising at least the outer surfaceof the lower portion must retain less than 70% of its tensile strength,its tear resistance or its shear strength.

In this embodiment, the submerged portion 2 is made of a material whosemain features are flexibility, resistance to water (hydrophobic), lightweight (weight of preferably less than 500 g/m²) and a specific gravityof less than 1. Another advantageous feature is to provide a very lowadhesion to marine organisms. This feature could optionally be improvedin the case of a durable device because these organisms must bedislodged as easily as possible for ease of cleaning. Example: PE,reinforced or not, can be specifically formulated or surface-treated toimprove the desired features.

In this embodiment, the submerged portion 2 may be partially or totallyreinforced with woven or non-woven fibers.

In this main embodiment, the complete device is provided with means forattachment 6 (loop, hole, grommet) and fastening 8 (straps, ropes,sandow cords, hooks . . . ) mainly placed on the emerged portion 1 whichallow for its placement and holding in place.

In another main embodiment, the emerged portion 1 and the submergedportion 2 are assembled together by a fastening system 4 which isreversible (FIGS. 10 to 14), i.e. fastening by means 4 (grommets, Velcrofasteners, clips, single or double sided adhesives, snaps, zippers)allowing for the simple and fast separation of these two portions.Portions 1 and 2 may therefore be dissociated for an optionalreplacement, of the lower portion 2 in most cases or of the upperportion 1 (for example in case of deterioration). For example, as anadvantageous detail, the lower portion 2 can be manufactured in a lesscomplex or thinner material which will be less expensive as aconsequence and allow for more frequent replacements. The attachmentmeans 6 are mainly placed on the upper portion 1 of the shell.

The two main embodiments detailed above allow for variants that can beapplied to both embodiments. We therefore define variants for theemerged portion 1 and for the submerged portion 2. These variants may beadvantageously blended in one or the other of the two main embodimentsof the complete device we call a shell.Below are detailed variants of the emerged portion 1 for the two mainembodiments

Below are given several examples of embodiments of the emerged portion 1of the device according to the invention:

-   -   The emerged portion 1 is composed of a plastic film of PVC        (polyvinyl chloride) optionally reinforced with a web.    -   The emerged portion 1 is composed of a plastic film that may be        selected from the following materials, optionally reinforced        (for example with a web): polyurethane, hypalon, neoprene,        polyester, polyethylene tetraphthalate, nylon, EPDM, Teflon, and        more generally all plastics having an ultraviolet resistance of        more than 3 years.    -   The emerged portion 1 may according to another manufacturing        embodiment be made of a layer of flexible plastic film and a        fabric or braided fibers 9, a net or any backing material 9 on        at least the surface (exposed to ultraviolet light) opposite to        the hull of the ship (FIG. 15).    -   The emerged portion 1 may in another embodiment consists of a        complexed plastic film (at least 2 layers) (FIG. 16). Example:        complex or multilayer, e.g. PVC/PE, PVC on the outer side for UV        resistance and PE on the inside optionally allowing for the        welding to the other PE building up the submerged portion 2.    -   The emerged portion 1 may be made of a specifically formulated        PE film (but more complex and expensive) for among other things        a superior UV resistance. Special additives can be added to the        PE base, e.g. carbon black pigments, UV (ultraviolet) absorbers,        flame extinguishing agents (quenchers) or polyfunctional        stabilizers, UV (ultraviolet) reflecting materials (e.g.        aluminum).    -   The emerged portion 1 may also be made of a plastic sheet of low        specific gravity (e.g. less than 0.8) providing adequate lift so        that this portion 1 floats, for example a foamed material 7        (such as EPDM or PVC) or any foam, in order to facilitate the        setting-up and positioning of the device.

The emerged portion 1 may consists of at least one outer film (exposedto ultraviolet light) and mostly opposite to the portion to protect, tobe selected from any of the following non-limiting materials: PVC,polyurethane, hypalon, nylon, with an ultraviolet resistance that issuperior to the materials making up portion 2, trapping a foamedmaterial 7, see FIGS. 21 and 22 (preferably with closed cells), orcovering it at least on its surface (exposed to ultraviolet light) andmainly opposite to the hull, see FIG. 23 (e.g. polyethylene, EPDM orPVC, or any foam).

Below are detailed variants of the submerged portion 2 for the two mainembodiments

Below are given several examples of embodiments of the submerged portion2 of the device according to the invention:

-   -   The submerged portion 2 consists of a polyethylene film or shell    -   The submerged film 2 consists of a film or shell of a plastic        selected from polyolefins    -   The submerged portion 2 is impervious to water.    -   The submerged portion 2 is permeable, drilled with a plurality        of holes of less than 4 mm², but sufficient to let through or        diffuse a fluid.    -   The submerged portion 2 may be comprised of at least 2 films of        materials having the same composition, i.e. several layers or        films forming an indivisible single layer or film, which when        assembled in a particular way provide different features due to        the multilayer complex. For example, a PE/PE complex where        layers are cross-orientated to increase mechanical strength.    -   The submerged portion 2 may itself be made of several films of        materials 2 and 2 b is (FIGS. 13, 17, and 22), of differing        compositions or thicknesses or physical features (non limiting        example: specific gravity). That is to say, of several        indivisible complexed layers (Example: PE/PP complex) or films        of the same material with specific distinct properties (e.g.        HDPE and LDPE), these films being non-cleavable complexes.    -   For the submerged portion 2, in the case of a complex of several        layers, the film or at least the inner layer which will be in        contact with the hull may advantageously be made of a material 9        (FIG. 18) facilitating the sliding against the hull        (non-limiting example: nonwoven polypropylene fiber, FIG. 18)        during the setting-up—and will protect the intermediate layer(s)        from tear.    -   The submerged portion 2 may be made of an anti-adhesive material        resistant to the adhesion of aquatic organisms (non-limiting        example: silicone film).    -   The submerged portion 2 may be rendered non-adhesive for        resisting to the adhesion of aquatic organisms at least on the        surface opposite to the portion 5 to protect, by introducing        anti-adhesive agents or glidants in the base material such as a        polyolefin, during the manufacturing process (non-limiting        examples: paraffin, stearate, oleamide . . . )    -   The submerged portion 2 may be made of a complexed material with        at least the outer layer or surface opposite to the surface to        protect made of an anti-adhesive material (in the case of a        multilayer outer film)    -   The submerged portion 2 may be made of a material of which at        least the surface opposite the surface to protect will be made        anti-adhesive by surface treatment after the film manufacturing.        The glidant (non-limiting example: silicone, paraffin) is        applied on the surface of the shell by coating, impregnation,        gluing or adhesive bonding, or        corona        process.    -   The submerged portion 2 may itself consist of several films of        materials the properties of which are identical or not,        cleavable or stripable, peelable, films adhering together with        the appearance of a single film comprised of several easily        separable layers. These complexes are constituted of easily        separable films, providing a way to remove and recycle a layer        as soon as it is deteriorated or covered with aquatic organisms.        These layers can be of various thicknesses e.g. a few microns        (non-limiting example: 10 to 60 μm)    -   The submerged portion 2 may be made of a plastic material on        which an active repelling or biocidal molecule is grafted to the        carbon chain during its manufacturing, for example a        chlorpyriphos-ethyl/bifenthrine.    -   The submerged portion 2 may be made of a plastic material on        which is included a repellent or biocidal product on at least        the surface opposite to the surface to protect.    -   The submerged portion 2 may be a complex wherein at least the        outer film opposite to the surface to protect contains a        repellent or biocidal product.

In another variant, the submerged portion 2 or 2 b is may be completelydisposable and recyclable (FIGS. 14 to 21) (or only the last layer inFIGS. 13 and 22) in case of e.g. aging or deterioration. This film maybe more fragile, thinner (non-limiting example: 40 μm) and thereforelighter, in order to reduce maintenance time before sailing, bysuppressing the cleanup phase of the submerged portion 2.

In another embodiment, the submerged portion 2 has a thickness of lessthan 500 μm.

In another embodiment, the submerged portion 2 is partially reinforcedby a strip of non-woven fibers or another additional film or layer 9(FIG. 20) in its upper portion on one surface of the submerged portion2.

In another embodiment, the submerged portion 2 is reinforced in areassuffering from friction or additional strain (propeller, keel . . . ) bya layer of non-woven fibers or another film to increase theirresistance.

In another embodiment, the submerged portion 2 may have imprints orembossings or is padded (e.g. geogrids or textiles) on its inner portionto allow for movement of fluids in the spaces created after contact withthe hull (FIG. 19).

According to Other Aspects of the Invention for the Entire Device

In one embodiment, the attachment means 6 are mainly placed on the upperportion 1 of the shell.

In another embodiment, the attachment means 6 are exclusively placed onthe upper portion 1 of the shell.

In another embodiment, the shell is open on the rear and the lowerportion 2 is in line with the upper portion 1 (FIGS. 3 and 4).

In one embodiment, the shell is open on the rear and the lower portion 2is set back with respect to the upper portion 1 (FIG. 5).

In one embodiment, the shell is open on the rear and the lower portion 2is set forward with respect to the upper portion 1 (FIG. 6).

In another embodiment, the shell may be closed on the rear by upwardfolding (FIG. 24).

In one embodiment, the shell is closed by crossing both sides of theshell and/or covering one side with the other on the rear (FIG. 25).

In another embodiment, the rear closing of the shell may be hood-shaped(FIG. 26).

In another embodiment, the shell may be closed on the rear by closing aflap downwards (FIG. 27).

In another embodiment, the submerged portion 2 is impervious andprovided with at least one check valve to let the trapped water leaveout and to preclude or minimize flow in the opposite direction.

In another embodiment, the submerged portion 2 is impervious andprovided with at least one valve or adjustable opening.

In another embodiment, portions 1 and 2 may have backing hems 11 throughwhich ropes or straps can be passed to adjust, place or tighten theentire device against the hull (FIG. 3).

The device is set up and maintained by ropes, sandow cords, carabiners8.

FIGS. 28 to 31 show an example of setting-up of the entire device.

1. Device for protecting an object floating or resting on an aquaticfloor having at least one submerged surface (5), comprising a flexibleshell suitable for wrapping around said submerged surface, wherein saidflexible shell comprises a lower portion (2) which when the shell is setup so as to wrap around the submerged surface, is mainly submerged andwraps around the majority of the submerged surface (5) to protect, andan upper portion (1) which, when the shell is set up so as to wraparound the submerged surface, is partly emerged, the upper portion (1)of the shell having a surface area inferior to that of the lower portion(2), in that at least the respective external sides of the upper portion1 and lower portion 2 of the shell are made of different materials. 2.Device according to claim 1, wherein the upper portion (1) and the lowerportion (2) are permanently assembled and affixed to each other. 3.Device according to claim 1, wherein the upper portion (1) and the lowerportion (2) are temporarily assembled.
 4. Device according to, claim 1,wherein the upper (1) and lower (2) portions of the shell are made ofmaterials of different densities.
 5. Device according to claim 1,wherein at least the outer side of the upper portion (1) has features ofultraviolet (UV) radiation resistance superior to those of the lowerportion (2).
 6. Device according to claim 1, wherein: the upper portion(1) of the shell is made at least on its outer side of one of thefollowing materials: PVC, polyurethane, hypalon, nylon, the lowerportion (2) of the envelope is mainly made of a polyolethylene film. 7.Device according to claim 1, wherein the upper portion (1) of the shellconsists of a plurality of layers of different materials, whethercomplexed or not to each other.
 8. Device according to claim 7, whereinthe upper portion (1) of the shell comprises at least two layers,including a substrate and a outer coating film onto the substrate andhaving higher UV resistance than the substrate.
 9. Device according toclaim 1, wherein the upper portion (1) of the shell comprises an innerlayer placed on the side of the object to protect or included in a hemand is made of a material of specific gravity lower than 0.9.
 10. Deviceaccording to claim 1, wherein the lower portion of the shell has aspecific gravity of less than
 1. 11. Device according to claim 1,wherein the lower portion of the shell has a weight of less than 0.5g/m².
 12. Device according to claim 1, wherein the lower portion of theshell consists of a plurality of layers of different materials, whethercomplexed or not to each other.
 13. Device according to claim 11,wherein the lower portion of the shell comprises at least one outerlayer at least partly separable.
 14. Device according to claim 1,wherein the lower portion of the shell is made at least on its outerside opposite to the object to protect, in a treated material which isformulated to provide anti-adhering properties.
 15. Device according toclaim 1, wherein the upper portion of the shell is provided with meansfor fastening it to the object to protect.